The present invention relates to compressors, and more particularly to a structure of suction valves of piston cooling compressors.
Known in the prior art are structures of self-acting suction valves for use in a compressor, comprising a seat, a lift stop, a valve plate and a spring accommodated between the plate and the lift stop (Cf. M. N. Frenkel, "PISTON COMPRESSORS", Leningrad Publishing House, 1969, p.p. 329 to 355; COOLING EQUIPMENT, Encyclopaedic Reference Book, vol.I, Publishers GOSTORGIZDAT, 1960, p.p. 212 to 214).
Prior art structures of suction valves, comprising a seat and a lift stop with a valve plate being arranged in the interspace therebetween are also known (cf. USSR Inventor's Certificates No.225,370 and No.479,396, Cl. F 04 b 49/00).
However, the prior art suction valves do not provide for a long service life and higher efficiency of the compressor since the valves are fitted with resilient members (springs) to ensure the closing of valves at the end of the suction stroke. For example, for closing the ring valves use is made of coil springs accommodated in the slots of the lift stop, whereas the plate valves whose plates are usually made of special steel, are closed at the expense of elasticity of the springs.
Thus, all the known structures of the self-acting suction valves of the compressor are closed under the effect of the valve resilient members (springs, elastic properties of plates). However, the use of resilient members in the valves substantially impairs reliability and reduces the service life thereof, determined, in this case by the rate of wear fatigue of metal and, depending on the rotation speed of the compressor, ranges within several thousands of hours. This is a very serious disadvantage which lies in that the speed of compressors is kept down within the range of from 1,000 to 1,500 r.p.m.